Former FBI Director James Comey's highly anticipated testimony before the Senate Intelligence Committee was watched by an estimated 19.5 million television viewers on Thursday, according to Nielsen data.

Cable news networks CNN, Fox News and MSNBC typically broadcast congressional hearings. But Comey's session — in which he called President Trump a liar — was a bona fide major media spectacle and received live coverage across the four major broadcast networks: ABC, CBS, NBC and Fox.

The broadcast network carriage boosted the ratings for the hearing, but its weekday morning airtime limited the size of the audience available to watch on TV.

Ratings for the hearing did not approach the 30.6 million viewers who watched the Jan. 20 inauguration of President Trump, the last major news event to air across all of the broadcast networks and cable news channels.

But Thursday's testimony made for some dramatic television and drew a healthy audience for daytime TV.

The viewership numbers may understate how many people actually watched the testimony. There is no official total for online viewing, as many outlets don't disclose their streaming numbers. CNN said its online audience peaked at 11:35 a.m. Eastern, with 767,000 simultaneous users watching its coverage, an indication that it was a significant audience across all available streams. CNN said there were 3.9 million "starts" to its online stream of the testimony. Bloomberg said it had an average of 129,000 users watching its live stream of the coverage on Twitter.

Those who tuned Thursday saw Comey tell the committee that Trump tried to impede an FBI probe into his fired national security advisor Michael Flynn's contacts with a Russian ambassador during the new administration's transition. Comey, who was dismissed by Trump on May 9, also accused the president and his administration of lying about him and defaming the FBI.

ABC had the largest audience, with 3.295 million viewers, followed by CBS (3.286 million viewers), Fox News (3.096 million), CNN (3.049 million), NBC (2.73 million), MSNBC (2.719 million), Univision (624,000), Fox Business Network (210,000), CNBC (164,000) and HLN (140,000). The hearing was also carried by Telemundo, PBS and was offered to Fox broadcast affiliates, which had the option to air it.